Wazzajnr wrote:

My L322 had 90k on the clock and lpg fitted (without flashlube) and is now on 140k and still fine.
I think a lot of the scare stories about weak valve seats are down to a poor lpg install.

I agree that some problems with excessive valve wear are due to poor installs. BUT you do need a valve lube on the Jag V8.

How do you know if your LPG install is good? (I would lol!).

So far you've done 50000 miles on LPG without a lube and without a problem, which is great. What we don't know is to what extent your valves have worn in 50000 miles compared to a Jag V8 with a lube system fitted, there may be no symptoms until valve seats have recessed to the point of causing poorer breathing due to valve shrouding or (extreme cases) lack of compression.

One of the worst offending LPG systems for causing VSR is the well regarded Prins VSI1 system. It is possible to set this system up so that at full throttle it switches to running it's own closed loop mode steering lambda voltage towards 0.5V (on an engine with narrowband probes... I know the Jag engine has wide band probes). The Jeep 4.7V8 engine normally doesn't need a lube system fitted but Prins advise a lube system for that engine - maybe because the generic settings that most Prins installers used when converting a 4.7Jeep activated this pseudo closed loop function.

The supercharged version of the Jag V8 needs a (electronic / forced) lube system more than the NA Jag V8 needs a (basic) lube system but they both need a lube.

50000 miles might not be enough to see any difference in engine performance but 100000 miles might be. I'd advise fitting one. For what a lube system costs to fit and costs to run, why risk accelerated valve wear... I fit a lube system by default (included in any quote) for any engine that is even borderline / grey area needing a lube system, with the Jag V8 a lube system is usually considered necessary, above borderline / grey area. I've seen some knackered Jag V8's and V6's (Ford based) due to VSR.

I've had caravans on and off since 1990, in recent years I've never bothered wiring up a 7S socket (intended and even fitted the double socket bracket on the towbar but never got around to it). My most recent caravan is still an old one 2004 model... so (being post '98) you reckon it will have the divider? I wonder how such divider works... I think I'd prefer the older spec wiring with full power to both the fridge and battery charging..

Thought car / towbar makers fitted: Older vehicles before easy production of voltage sensing relays - 2 wires from the car, one from the battery, one from the ignition switch. Newer vehicles since easy production of voltage sensing relays - single thick wire from the battery to near the 7S socket, voltage sensing relay disconnects the fridge when car battery voltage is below around 12.7V (car side of the socket).

Maybe check voltage at the caravan battery when the fridge is running to make sure it seems to be charging or on a longer drive the caravan battery might be nearly flattened? Not so much a problem these days when everyone stays on a site with 240v electric and caravans have built in battery chargers but in the old days if intention was to do some touring around, no 240v on sites so no battery charger so relying on the car charging the battery up... the old way might have been better, might even be better these days?

Someone had tampered with wiring on one of the caravans I owned, the fridge and battery charging wires were joined in the caravan, this did lead to the caravan battery being almost flattened on longer trips despite my having run a hefty wire from the vehicle battery to the 7S socket until I sorted it.

dhallworth wrote:

Our caravan fridge can draw 10A when it's running so it's on a switched live to protect the tow car battery. As long as you don't open a fridge door, it'll stay cold during a power cut for a long time so it's not an issue when you stop the car for an hour or two during travels.

The permanent live is for the caravan water pump and lights so that you can use them when you stop if needs be.

One of the main problems is the wiring loom for the P38 from LR is for caravan electrics Pre 98, they changed in 98 but still used the 12S socket. I'm trying to wire mine into a 13 pin socket when they changed again. Instead of having Permanent 12v, Switched 12v and Battery Charging, they changed the electrics in the caravan to include a habitation relay which divides the Permanent 12v between the fridge and the battery charging so you could in theory end up with one hell of a current draw on the switched 12v now.

Anyway, I sat down with a pen and paper last night and drew a new circuit diagram and with a bit of modification to the LR kit I've bought I now know how I can get it all wired in :)

David.

How does the habitation relay work? I thought the separate 7S pins for fridge and caravan battery charging were supposed to have separate feeds from the vehicle battery.. Ideally you want it set up so that the fridge will run from the car and the caravan battery will be charged at the same time?

Car
battery
feed 1 > socket > fridge
feed 2 > socket > caravan battery

If there's only one feed or the feeds are connected in parallel too close to the caravan (too far to the right in the above excuse for a diagram), then due to the caravan battery being so much closer to the fridge (in wire / resistance / voltage drop terms) than the vehicle battery it's likely that the caravan battery will lose some of it's charge (rather than be charged) due to the fridge drawing most of it's power from the caravan battery? To charge the caravan battery there'll have to be 13+V at the caravan battery even with the load of the fridge but with a single feed there might only be 12v unless the feed is rather thick for little voltage drop under load?

With a separate feed the only difference thickness of feeds could make is how quickly the caravan battery gets charged and how cold the fridge could get, both independently..
Does the habitation relay thingy have some sort of voltage sensing relay that only connects the caravan battery to charge above a certain voltage at the caravan, some sort of DCDC converter, just some sort of double throw relay which continually switches between charging the battery and powering the fridge, etc?

There's a difference between calorific values, stochiometric ratios and octane ratings between petrol and ethanol and none flex fuel rated engines / ECUs couldn't run well on E85 but should run OK on E10 provided they run closed loop fuel injection (or carb / open loop with mixture adjusted) and don't have rubber in fuel lines.

Ethanol can increase octane rating but despite that will usually produce less power due to the other factors.

Before ethanol was added to petrol LPG pipe could be used for petrol. Ethanol turns rubber LPG pipes to mush but Faro/polypipe isn't affected.

L322's with the BMW V8 suffer cam cover rear breather pipes turning to mush, possibly due to ethanol vapour (possibly an oversight on BMW's part but I forget when ethanol started being added to petrol)..?

Does the cruise control status use bit indicators for each aspect such as cruise on/off, clutch position, etc ?

This isn't a Rangerover specific answer but I'd say yes for most vehicles for the same reason Gilbert said.
Recently had a similar discussion on LpgForum regards a supercharged L322, seems many of the vehicle's problems were caused by an aftermarket 'compatible' MAF, which went away when the genuine part was fitted.

'Uncoiled the wire' - Do you mean the reducer temp sensor wires you shorted together?

How long since it last ran well on LPG?

Have you done the reducer diaphragm test and injector leak test?

Cut the 2 wires to it (leave enough on the sensor side of the cut so you can rejoin them if it turns out to be a good sensor) and on the LPG ECU side of the cut join the 2 wires together.

While you're at it you could check resistance across the sensor itself.

Dream reducers usually have the wide (M10 / M12) thread for the temp sensor.

If necessary (if your temp sensor is broken) you should be able to remove that temp sensor if you follow my earlier removal advice. But you've said you've found yours has an M6 thread... have you removed it to check? The sensor in the pic definitely looks standard Dream fitting with the wider thread.

OMVL branded Dream reducer temp sensors have a plug on the end of wires. The one you've seen on Ebay should fit Dream reducers but it isn't an original OMVL part because it doesn't have the plug. Since your install has a Stag ECU (instead of OMVL ECU) the loom itself wouldn't have the corresponding plug so the installer will just have cut the OMVL sensor's connector off and spliced the wires in, you'd have to do the same.

Since your Stag ECU will be an older one you should be able to short the temp sensor wires to get it to change to LPG as Bri says, if it were a later ECU shorting the wires would cause the ECU to flag an error (for shorted temp sensor...) and it still wouldn't switch to LPG, in which case you could put a 1K resistor across the temp sensor wires rather than shorting them.

Some inline (in pipe) water temp sensors are OK, some are very prone to water leaks. Most temp sensors are designed to fit in a blind hole in a reducer, some of the in pipe setups use sensors designed to fit into blind holes in reducers in a through hole in the bit that fits in the pipe with just some thread seal and/or a little O ring (but the sensor isn't designed for an O ring).

If you do replace one of the reducer's bolts with a temp sensor make sure you get a sensor of correct thread diameter and at least long enough length. You can cut the threaded end of temp sensors shorter. There are several diameters of temp sensors but iirc the most common sensors are a different diameter to Dream reducer bolt threads, a temp sensor that will fit in e.g. a KME reducer won't fit in place of a bolt in a Dream reducer.

Ideally (if your sensor is broken) you'd replace it with a sensor to fit in the same position rather than fitting a sensor in place of a bolt. The front housing of Dream reducers (where bolts fit) warms slower than the usual temp sensor position. As Bri says, if it's broke try removing it (method I mentioned in earlier post), if you can remove it replace it, if you can't remove it it might be a better idea to fit an line type (a good one) than replace a bolt with a sensor.

Yes the usual position for the temp sensor on a Dream reducer is on top of the reducer, it would he hidden under the pipes in your pic... Unless someone has fitted a sensor designed to fit another type of reducer in place of one of the reducer bolts as Gilbert said.

"LPG injectors £288".... 1 Year after installation - so much for Profess' supposed lifetime warranty! Those injectors will only have cost about £70 at the time.

If there were a broken coil it would still try to switch so would beep back to petrol with no gas pressure.

Yes, try the resistance of the reducer temp sensor. Move the temp sensor wires around where they connect to the sensor during the test.

It's an OMVL Dream reducer and OMVL Superlight injectors but judging by the switch the LPG ECU won't be AEB/OMVL, it will likely be something like an early(ish) AC Stag ECU.

If the switch beeps (as though you've run out of gas) it's trying to switch to gas but detecting low gas pressure so switching back to petrol as though you've run out of gas... Usually a solenoid problem.

If there are no clicks from solenoids and no beeps from the switch it won't be trying to switch to LPG, begging the question why it isn't trying to switch. The usual reason is a low temperature reading from the reducer (either the reducer really isn't getting warmed by flow of hot water or the reducer temp sensor is broken), lack of RPM signal, or if the manifold pressure sensor reads no vacuum (some system's won't switch if it seems the engine is running full load with no manifold vacuum... although Stag usually will switch even at full engine load with no manifold vacuum).

Temp sensors are a common failure on Dream reducers, especially if wires to them are tightly tie-wrapped to hoses connected to the reducer (moving the hoses pulls on the wires to the temp sensor)...If the reducer is getting hot to touch try checking the resistance across the temp sensor, should be a couple of K Ohms (it's an NTC sensor so open circuit reads extremely cold, short circuit extremely hot). They're usually corroded in on Dream reducers (dissimilar metals the temp sensor is brass), to replace it's best to cut the wires off and use a hex socket (usually 12mm). The temp sensor is shallow and easily rounded off so if the hex socket opens up at the end it's best to grind the socket so the socket's hex gets full purchase on the hex of the sensor.

Stag ECUs had the option of detecting RPM from injection pulses (instead of from a coil or rpm feed) earlier than AEB ECUs, still early Stag ECU's needed an rpm connection.

Some systems refuse to switch to LPG if they read no manifold vacuum (to prevent switching fuels during full engine load), though Stag don't usually do this. Still, since it's easy to check the vacuum connection from manifold to vacuum sensor it's a check worth doing early on. Don't forget that the map sensor vac line is usually T'd to the reducer, if the vac pipe is broken/disconnected at any point it could see the map sensor reading no vacuum.

That's good then, a simple and relatively inexpensive fix.

I've been on the floor under many thousands of vehicles for extended periods including hundreds of P38s.

If I'm doing 'on the floor' and not working on wheels/suspension my favourite method for raising a vehicle is to drive it onto concrete blocks.

But with Rangerover's it's so handy to be able to press a button and have the car lift itself up, no driving onto concrete blocks necessary.

With most of the Rangerovers I converted I just pressed the button and crept underneath, loads of headroom. On only a few of the Rangerovers I've been under have I felt it necessary to prop the body (including a few P38s I converted that were on bump stops when they came in...).

If I have to jack anything I'll try to leave both jack and axle stands under the vehicle sharing the weight and adding stability. Still, if a spring failed... But considering the vehicle has been driving around for years/miles and the spring hasn't failed it would have to be 'my time' and a freak accident for anything that untoward to happen. Although electronics on Rangerovers may decide to vent air from airbags at anytime, or airbags might suddenly blow, I've come to trust that won't happen.

But I do sometimes push the risks a bit... some of you have seen (on forum) pics of the Nissan I had resting on gas tanks while I dropped it's engine out from below..

After addressing all the obvious crush safety concerns my biggest worry under cars is the amount of crap I'll be getting in my eyes. I get loads of bits in eyes, mostly very minor issues but around 3 times per year I'll get something in an eye that messes with my eyes for several days. Can't wear goggles etc, can't see well enough through them.

Looks brand new or like a concourse show car.

How much will it be worth after all this?

I've ground quite a few spanners thinner...

Gilbertd wrote:

By the way, you'd be welcome to join us for a pint tomorrow evening https://rangerovers.pub/topic/1775-a-night-out-at-the-pub

No need to rub it in if he can't currently buy beer in SA? lol..

I dunno about Raspberry Pi based BeCMs but people have built fuel injection ECUs from Raspberry Pi's, various videos on YouTube including one of an Indian guy who based his motorbike's fuel injection system on a Pi.

I'm tinkering with a similar idea but where the output from the Pi (or whatever) is used as input for an LPG slave ECU... could call it a slave driver ;-) All it needs to do is output a pulse per rpm pulse (or rpm pulse divided by 2 / multiplied by 2 / etc) with pulse length keyed to manifold pressure (e.g. 1 bar map = 10ms pulse, 0.5bar map = 5ms pulse length, etc). The range of pulse lengths it provides isn't critical because the actual tuning could be done in the slave LPG ECU's map. Could be made closed loop if it adjusts pulse length according to lambda voltage, could even have it's own fuel trims but to have it's own fuel trims it would ideally need to store a table for trims at different combinations of manifold pressure and rpm. Wouldn't even need it's own map sensor because the LPG system will have a map sensor. Standalone EFI LPG systems exist but are relatively expensive and modern such systems are incapable of running closed loop, this setup would be less expensive and the installer could use it in combination with almost any LPG ECU they preferred to use. Functionality of the unit could be increased, for example it could switch external emulation of LPG injectors to allow instantaneous switching to LPG (by switching from emulated LPG injectors to actual LPG injectors) when petrol from a carb float bowl runs out.

I've worked on a P38 that wouldn't start with the MAF disconnected but wouldn't run with it connected (or vice/versa, I forget which way around it was). Certainly a duff MAF can cause inability to run (bet Gilbert would remind everyone except with an LPG mixer system ;)

There's fuel pressure... but is there fuel pressure when the engine is running? And is fuel pressure correct when the engine is running (pump isn't haphazard and the fuel pressure regulator backs of fuel pressure with rising manifold vacuum)? They run very rich initially during cranking and just after starting, especially when the engine is cold and in cold weather.

They could probably start and run for a brief period with half the fuel they normally get for cold start conditions but with half the fuel they wouldn't run for long before leaning out and stalling. Very low or (less likely) very high fuel pressure could give the symptoms.

Usually a naff crank sensor would hinder starting too - crank sensors can be affected by temperature but between a cold engine to start and the engine running for a moment before stalling the crank sensor temperature will be almost the same.

A vacuum leak could cause it but it would probably have to be quite severe...

Others will know more about whether there's some system that powers up the fuel pump during cranking but relies on an engine running signal from the ECU to keep the fuel pump powered up?

Even less likely, severely block cats could cause the symptom, probably unheard of on a P38?

In the mid 90's at about 3am on a Sunday morning I was driving back from Liverpool to home in Yorkshire on the M62 in my Vauxhall Senator at about 130mph, not flat out, just cruising at a high speed with hardly any other traffic on the road. I saw another car way behind slowly catching me up but it had no police markings, at the time there were few unmarked police cars anyway, I considered the car was approaching from so far behind that it was unlikely I'd gone passed it while it was parked up somewhere and it was trying to catch up to me so I thought it would just be someone doing the same as me. I stayed at the same speed as it overtook me and as it went past I looked across at it. I saw it was full of policemen, probably middle aged officer ranks! The front and rear passengers both gave me a look as they went past but they didn't pull me, just continued on their way as both cars maintained the same speeds we'd been doing. I gradually slowed down to under a ton to put some distance between us in case they changed their mind lol. I wondered that if I'd been in a different car, maybe something they knew I'd have to have foot to the floor in to do 130mph, or if it was a different time of day and traffic was busier, they might have thought I was speed testing the car, racing or driving recklessly and pulled me. On another occasion I was stopped for speeding in my Vauxhall Senator by police in an Vauxhall Omega, we had a chat about the cars and they told me if I'd decided to try to do a runner it was unlikely their Omega could have kept up with my Senator, I told them 'yes but your roadblocks and helicopters would catch me', they ended up letting me off lol.